Security update for libreoffice (moderate)

This update for libreoffice to 6.0.5.2 fixes the following issues:

Security issues fixed:

• CVE-2018-10583: An information disclosure vulnerability occurs during
  automatic processing and initiating an SMB connection embedded in a
  malicious file, as demonstrated by
  xlink:href=file://192.168.0.2/test.jpg within an office:document-content
  element in a .odt XML document. (bsc#1091606)

Non security issues fixed:

• Bugfix: Table borders appear black in LibreOffice (while white in
  PowerPoint) (bsc#1088262)
• Bugfix: LibreOffice extension ‘Language Tool’ fails after Tumbleweed
  update (bsc#1050305)
• Bugfix: libreoffice-gnome can no longer be installed in parallel to
  libreoffice-gtk3 as there is a potential file conflict (bsc#1096673)
• Bugfix: LibreOffice Writer: Text in boxes were not visible (bsc#1094359)
• Use libreoffice-gtk3 if xfce is present (bsc#1092699)
• Various other bug fixes

This update was imported fromm the SUSE:SLE-15:Update update project.